The promise of large-area, flexible organic electronic devices has intrigued numerous research groups with efforts directed towards the understanding of charge injection and transport, crystal engineering of molecular solids, and device design. Various groups have been involved in the development and understanding of arylene n-type semiconductor materials for organic field-effect transistors (OFETs). As the OFET performance of molecular semiconductors has improved, the optimization of the optical and mechanical properties of these materials has advanced to yield all-organic, flexible, solution-cast, and optically transparent device structures. Particularly, transparent electronic materials in the visible region are of interest for applications in display technologies; however, current transistor technology is based upon opaque amorphous silicon. While several attempts have been made to fabricate p-channel transparent OFETs, these efforts have suffered from the large extinction coefficient absorptions in the visible spectrum for most organic semiconductors. Comparable challenges remain in the n-type context.
Among n-type organic semiconductors used in OFETs, the class of arene core diimides is one of the most investigated. The first report on a diimide-based FET was on a series of naphthalene tetracarboxylic diimides (unsubstituted core), followed by reports of perylene tetracarboxylic diimides. Over the years, chemical modification and tailoring of the imide position has resulted in the production and testing of a library of diimide-based materials. However, such compounds have been found generally to be unstable in air and have solubility characteristics that are less than satisfactory for efficient device fabrication.